I am new to this site and have been reading lots about women having trouble with weight gain on medication for PP and also wanting to breastfeed while on medication for PP.
When I had PP after the birth of my 4th child I was put onto Zyprexa. I could breastfeed on this medication but it caused me to gain a lot of weight. I was then switched over to Saphris (asenapine) and to my knowledge it does not have any side affects and you can breastfeed while on it.
Hope this is helpful to others.